Maker missions

Challenges to stretch your brain

Each challenge gives you a goal and some starter code. Try it yourself first, peek at a hint if you get stuck, then read the explanation to see the idea behind the solution.

Your maker points

0 of 90 points · 0 of 5 challenges done

💡Beginner 10 pts

Blink an LED in a Pattern

Goal: Make a single LED blink the SOS signal: three short flashes, three long flashes, three short flashes, then a two second pause before repeating.

starter.ino

const int LED = 13;

void setup() {
  pinMode(LED, OUTPUT);
}

void blink(int onTime, int times) {
  // your code here
}

void loop() {
  // three short, three long, three short
}

⏱️Intermediate 25 pts

Build a Reaction-Time Game

Goal: After a random wait of 2 to 6 seconds, light an LED. Measure how many milliseconds pass before the player presses the button, and print the score to the Serial Monitor. Catch cheaters who press early.

starter.ino

const int LED = 9;
const int BUTTON = 2;

void setup() {
  pinMode(LED, OUTPUT);
  pinMode(BUTTON, INPUT_PULLUP);
  Serial.begin(9600);
  randomSeed(analogRead(A0));
}

void loop() {
  // 1. wait a random time
  // 2. light the LED and remember millis()
  // 3. wait for the press and print the difference
}

🦿Beginner 15 pts

Move a Servo to Different Angles

Goal: Sweep a servo smoothly from 0° to 180° and back, then make it pause for one second at 0°, 45°, 90°, 135° and 180° on the way.

starter.ino

#include <Servo.h>
Servo arm;

void setup() {
  arm.attach(9);
}

void loop() {
  for (int angle = 0; angle <= 180; angle++) {
    arm.write(angle);
    delay(15);
    // pause at each checkpoint
  }
}

🌡️Intermediate 20 pts

Create a Temperature Warning System

Goal: Read a temperature sensor and show three states with LEDs: green below 25 °C, yellow between 25 and 30, red plus a buzzer above 30. The system must not flicker when the temperature sits right on a boundary.

starter.ino

const int SENSOR = A0;
const int GREEN = 5, YELLOW = 6, RED = 7, BUZZER = 8;
bool alarmOn = false;

float readCelsius() {
  float volts = analogRead(SENSOR) * 5.0 / 1024.0;
  return (volts - 0.5) * 100.0;
}

void loop() {
  float t = readCelsius();
  // choose a state, then apply hysteresis to the alarm
}

📡Intermediate 20 pts

Make an Ultrasonic Sensor Detect Objects

Goal: Measure distance with an HC-SR04 and make a buzzer beep faster the closer an object gets — like a car parking sensor. Below 10 cm the tone should become continuous.

starter.ino

const int TRIG = 10, ECHO = 9, BUZZER = 8;

int distance() {
  digitalWrite(TRIG, LOW);  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH); delayMicroseconds(10);
  digitalWrite(TRIG, LOW);
  return pulseIn(ECHO, HIGH) * 0.034 / 2;
}

void loop() {
  int d = distance();
  // map distance to beep speed
}

Finished them all?

Invent your own challenge, build it, and show it off to the community.

Share your build